*This is a comprehensive guide on how to upgrade the various items in your base in an order that makes you an asset to your clan in war, to a significantly greater extent than if you upgraded your base by maxing everything out.
- Side Note: Resource buildings (storages, mines, collectors and drills) have very little effect on war weight (of which you want to keep low to have success in war as detailed below), therefore feel free to max those or not max those as you like.
~War Weight Mechanics~
*Definition of th: town hall - example: th7 = town hall 7
*Important Note: When troops and troop levels are reffered to in the following sub-section, this is reffering to the troops you use in your war attacks, all troops have some weight depending on the level (It is somewhat low, espically compared to defenses, but still matters to some extent, therefore the best choice is to refrain from upgrading troops, you do not use, at all).
The levels of your buildings, troops, heroes and walls all have specific values that determine your weight in war. For most players with conventional bases, their weight in war is mostly accounted for by their defenses and partially accounted for by their walls, heroes and troops. This is due to the fact that defenses have a great deal of the weight for any given town hall level for bases with defenses at the same strength as troops, heroes and walls. This critical distinction means that prioritizing your defenses will result in your base having a high war weight for your level and for your offensive strength. Therefore, In war, prioritizing defenses will make it significantly harder on average for you to 2 star or 3 star your "equal" (the same number base as you). Consequently, Prioritizing your offense in war (troops & heroes) and walls (as they're benefit is high and they're war weight is quite low) in war will make it significantly easier on average to 2 star or 3 star your equal.
This means that the stronger your offense and the weaker your defense, the better your war performence will be in general (asuming your attacking skill is static which you'd have to factor in for comparison from one specific defensive & offensive strategy to another) Using this metric, the ideal base is one with only a level 1 cannon (because you're foreced to build it in the tutorial), no walls and maxed out th11 offense (now to be realistic there's very few players in the game willing to build such an account but it's the best account for war one could possibly have). The worst base being one with lv1 barbs unlocked and that's it, no heroes built, max th11 defenses and 275 level lv7-9 walls (because at the th11 level walls are only a significant enough problem for ground attacks to likely have a worthit affect on defense past level 9).
~Realistic and Practical Base Scenarios~
~Concerns, admittance and "rushing"~
Arguably the most common complaint with bases that have lower than normal level defense (for their town hall level) is that the player is "rushing their base" and therefore not a serious player, this can make it more difficult to enter prestigous clans (for example; clans associated with YouTube channels) but the more serious war clans usually understand the benefits of the strategies detailed in this guide(in the early 2016 meta these often can be identified by their level which, at said point in time would be level 8 or higher usually) and of course clans with low standards will have such standards regardless unless we're talking about a really "strict" clan. And if the clan you're already in begins to give concern about you "rushing" feel free to expain the mechanics yourself or direct them to this guide.
- (I spell out th in the begining of the 3 following sections including th8.5 to attempt to really spell out the point better).
Town hall 8.5, as it is halfway inbetween a town hall 8 base and a town hall 9 base, is a town hall level 9 base with town hall 9 offense and town hall 8 defense. This is a very significant move from a maxed out town hall 8 towards priortizing offense and therefore increasing your chances to 2 or 3 star your equal quite significantly as one would have slightly more than the war weight than that of a maxed town hall 8 but with an archer queen and town hall 9 troops including but not limited to hounds, witches and lv4 golems for instance (which are a huge upgrade from the lv2 ones at th8).
To simplify the process, a th8.5, in terms of defense, should (generally, lower level defense is fine execpt for admittence purposes) have 5 lv(level)10 cannons, 5 lv10 archer towers, 4 lv6 mortars, 3 lv6 air defense, 3 lv6 teslas, 3 lv6 wizard towers and 1 lv4 air sweeper (0 xbows), meaning you do not build any xbows or new defense for this to work optimally, the base in question needs to build NONE of the new defenses for th9 and it needs to not upgrade any existing defenses (this is assuming that said base has maxed th8 before upgrading to th9 which is reccomended other than maxing defenses which is not ideal but having defenses lower level than the maximum for the th level below you makes it harder to get into prestigous clans. The base in question, after having upgraded to th9 needs to build the archer queen, upgrade all 4 army camps to lv7, the clan castle to lv5, the labratory to lv7, the spell factory to lv4 and both dark barracks to lv6. After doing those basic offensive upgrades, the base is th8.5 and may reap the benefits of those efforts by having a significant advantage in war, if the player is skilled enough, at th8.5, 3*ing any th8 should then be easy with said th9 offense using strategies such as lavaloon (lava hounds and balloons) and gowiwi (golems, witches and wizards).
*Important Note: Depending on the will-power of the person with the base (or bases) in question, they may not want to attempt any of these strategies due to the fact that a player who is not the most patient and has trouble resisting excitement for and temptation to build new defense and upgrade currently existing defenses may upgrade their town hall, for example, to level 9, before maxing out and after, say, 2 weeks of attempting th8.5, such a player with said traits may be likely make the mistake of building xbows and make war matchups he participates in more difficult as a result therefore ruining the entire point of upgrading to th9 early or at all for war purposes in the first place.
As offensive items have low weight in war and you want to prioritze them, once you establish th9 offense with th8 defense you want to continue by upgrading only your heroes, walls and troops of which you use, a lot of emphasis is warrented for focusing on reaching high wall levels and hero levels (lv9+ walls and lv20+ heroes) before starting to build new defense (which is never neccessary to improve your success in war) and the same goes for th9.5s and 10.5s building new defense (for th9.5 I reccomend waiting until you have lv10+ walls and lv35+ heroes and for th10.5 I reccomend waiting until you have half lv11, half lv10 walls or better, a lv 40 archer queen and barbarian king and a lv10 grand warden)
Town hall 9.5 (similiar to town hall 8.5) is a town hall level 10 base with town hall 10 offense and town hall 9 defense. Just like an 8.5 base, th9.5 bases have significant advantage in war by having only slightly more war weight than a th9 with the full benefits of th10 offense. This allows th9.5s to use attacks that rely on items including (but not limited to): higher level heroes, high level freeze, strong pekka to the extent of usefullness (as lv3 pekka have limited applications at th9 for 3 starring bases).
Defensively, a th9.5 should have 6 lv11 archer towers, 5 lv11 cannons, 4 lv7 mortars, 4 lv7 air defense, 4 lv7 teslas, 4 lv7 wizard towers, 2 lv5 air sweepers and 2 lv3 xbows, meaning you do not build any inferno towers or other new defenses (for this strategy to function optimally). After having upgraded to th10, the base in question needs to upgrade army camps to lv8, the clan castle to lv5, the labratory to lv8 and the spell factory to lv5. After that, just like a th8.5, the th9.5 may reap the similar offensive benefits by using strategies that might be very similar to strategies to th9 but much stronger.
Town hall 10.5 (similar to the previous 2 strategies) is a town hall level 11 base with town hall 11 offense and town hall 10 defense. Just like an 8.5 and a 9.5, the th10.5 base has a significant advantage in war for the same reasons as the previous 2 strategies, more specifically due to the extra benefits of having a grand warden (given his exceptional aura capability and immunity ability) and lv3 witches (I would reccomend leaving your minions at lv5 or 6 since they are not useful troops other than for farming with loonian (balloons and minions).
Defensively, a th10.5 should have 7 lv13 archer towers, 6 lv13 cannons, 4 lv8 mortars, 4 lv8 air defense, 4 lv8 teslas, 4 lv8 wizard towers, 2 lv6 air sweepers, 3 lv4 xbows and 2 lv3 inferno towers (which may not even be worth not building depending on your attacking skill to mach opponets' attacks on your base). This means you should not build the eagle artillery. After having upgraded to th11, the base in question needs to build the grand warden and upgrade the labratory to lv9 (afterwords, of course, they should upgrade witches, as lv3 witches are very useful in the current (early 2016) meta and leave minions at lv5 or 6). This allows the use of a much stronger dragon attack and a very powerful gowiwi (with the help of lv3 witches).
Creating a base that, defensively, has no more than 1 lv1 cannon and no walls (or just enough to surrond the cannon upgraded to max, which is debateably not as optimal) is creating what is called a defenseless base which is not listed under the 2nd topic as it is much more practical than any of the previous strategies if brought up to th6 or higher but it is not that realistic such that the vast majority of players do not have the determination to make such an account (which explains why they are so rare) as you are practically garenteed to have all of your available resources taken every time you defend (minus what you collect back from loot carts). It becomes much more difficult starting at th7 as you have to start saving dark elixir in this difficult, defensive situation. It is still very feesable up to obtaining max th9 troops and level 20 heroes but after that, the upgrading process becomes exceptionally difficult, it's a "fun" challenge but the farther you take a defenseless account, the more beneficial said account is in war. Simply imagine the ramifications, for example, say, there's a clan with 20 defenseless, max th10 offense accounts and they start a war, they are likely to be placed against 20 opposing players at roughly th7 offense and defense, talk about a mismatch, it's much deserved perhaps due to the sheer amount of determination it takes to farm lv40 heroes, for instance, on a defenseless account, while this is the extreme it can be achieved, and most likely will be achieved in the coming months if it hasen't been already, but regardless, this is the most difficult and most successful way to upgrade accounts for war purposes.
*For credibility sake, for those who may be curious, my main account is a 9.5 with mostly lv10 walls and 24 & 26 heroes currently and I also have a defenseless th7 account as well as another normal th7 account, I find nothing but success with the strategies above.